BCL and FCL both are NameSpaces?

I need a clarity regarding class libraries.
Base Class Libraries and Framework Class Libraries both are comes under namespaces-I mean can we call both are namespaces? if not which one we can call as a namespace and why?

No, they're not namespaces. A namespace is something like System, System.IO or System.Collections.Generic. The libraries contain types that are in namespaces, but the libraries aren't namespaces themselves.

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